Dual-flange prosthetic valve frame

ABSTRACT

Embodiments of prosthetic valve frames for implantation within a native mitral valve can include a main body portion, and first and second radially extending flanges coupled to the main body portion. The flanges can be coupled to the main body such that the flanges are spaced father apart from one another when the main body portion is in a crimped configuration than when the main body portion is in an expanded configuration. Associated delivery systems and methods of delivery are provided.

CROSS-REFERENCE TO RELATED APPLICATION

The present application claims the benefit of U.S. ProvisionalApplication No. 62/040,099, filed Aug. 21, 2014, which is incorporatedherein by reference.

FIELD

The present disclosure relates to implantable devices and, moreparticularly, to prosthetic valves for implantation into body ducts,such as native-heart-valve annuluses.

BACKGROUND

The human heart can suffer from various valvular diseases, which canresult in significant malfunctioning of the heart and ultimately requirereplacement of the native heart valve with an artificial valve. Thereare a number of known artificial valves and a number of known methods ofimplanting these artificial valves in humans.

One method of implanting an artificial heart valve in a human patient isvia open-chest surgery, during which the patient's heart is stopped andthe patient is placed on cardiopulmonary bypass (using a so-called“heart-lung machine”). In one common surgical procedure, the diseasednative valve leaflets are excised and a prosthetic valve is sutured tothe surrounding tissue at the native valve annulus. Because of thetrauma associated with the procedure and the attendant duration ofextracorporeal blood circulation, some patients do not survive thesurgical procedure or die shortly thereafter. It is well known that therisk to the patient increases with the amount of time required onextracorporeal circulation. Due to these risks, a substantial number ofpatients with defective native valves are deemed inoperable becausetheir condition is too frail to withstand the procedure.

Because of the drawbacks associated with conventional open-chestsurgery, percutaneous and minimally-invasive surgical approaches are insome cases preferred. In one such technique, a prosthetic valve isconfigured to be implanted in a much less invasive procedure by way ofcatheterization. For instance, U.S. Pat. Nos. 7,393,360, 7,510,575, and7,993,394 describe collapsible transcatheter prosthetic heart valvesthat can be percutaneously introduced in a compressed state on acatheter and expanded to a functional size at the desired position byballoon inflation or by utilization of a self-expanding frame or stent.

SUMMARY

In some embodiments, an implantable prosthetic valve comprises aradially collapsible and radially expandable, annular, main bodydefining a lumen therethrough, a first flange coupled to the main bodyand extending radially away from the main body, the first flangecomprising a plurality of radially extending first protrusions, a secondflange coupled to the main body and extending radially away from themain body, the second flange comprising a plurality of radiallyextending second protrusions, and a valve member supported within thelumen of the frame, wherein the first flange and the second flange arecloser to one another when the main body is in a radially expandedconfiguration than when the main body is in a radially collapsedconfiguration, and wherein each of the first protrusions and each of thesecond protrusions comprise a first radial strut coupled to a first nodeof the main body and extending radially away from the main body, asecond radial strut coupled to a second node of the main body andextending radially away from the main body, a first angled strut coupledat an angle to the first radial strut, and a second angled strut coupledat an angle to the second radial strut and coupled to the first angledstrut.

In some embodiments, the valve member defines an inlet end and an outletend of the implantable prosthetic valve, and the first flange and thesecond flange are coupled to the main body at locations located closerto the inlet end than to the outlet end of the implantable prostheticvalve. In some embodiments, the valve member defines an inlet end and anoutlet end of the implantable prosthetic valve, and the first flange andthe second flange are coupled to the main body at locations locatedcloser to the outlet end than to the inlet end of the implantableprosthetic valve. In some embodiments, the distance between the firstflange and the second flange when the prosthetic valve is in theradially collapsed configuration is larger than the thickness of thenative human mitral valve annulus, and the distance between the firstflange and the second flange when the prosthetic valve is in theradially expanded configuration is smaller than the thickness of thenative human mitral valve annulus. In some embodiments, the firstprotrusions are angularly offset from the second protrusions.

In some embodiments, the main body has a first end and a second end, andcomprises a network of struts interconnected at a plurality of nodes toform a plurality of open cells; the first protrusions are coupled tofirst nodes of the main body at the first end of the main body; and thesecond protrusions are coupled to second nodes of the main body, whichare displaced toward the second end of the main body from the first endof the main body by the smallest increment available. In someembodiments, the main body has a first end and a second end, andcomprises a network of struts interconnected at a plurality of nodes toform a plurality of open cells; the first protrusions are coupled tofirst nodes of the main body at the first end of the main body; and thesecond protrusions are coupled to second nodes of the main body, thesecond nodes being the closest nodes in the network of struts to thefirst nodes. In some embodiments, the main body has a first end and asecond end, and comprises a network of struts interconnected at aplurality of nodes to form a plurality of open cells; the firstprotrusions are coupled to first nodes of the main body at the first endof the main body; and the second protrusions are coupled to second nodesof the main body, the first nodes and the second nodes being situated ina single circumferential row of open cells.

In some embodiments, the first flange extends radially away from themain body such that an angle between a side of the main body and thefirst flange is between about 70° and about 110°, and the second flangeextends radially away from the main body such that an angle between aside of the main body and the second flange is between about 70° andabout 110°. In some embodiments, the first flange extends radially awayfrom the main body such that an angle between a side of the main bodyand the first flange is between about 80° and about 100°, and the secondflange extends radially away from the main body such that an anglebetween a side of the main body and the second flange is between about80° and about 100°. In some embodiments, the first flange extendsradially away from the main body such that an angle between a side ofthe main body and the first flange is about 90°, and the second flangeextends radially away from the main body such that an angle between aside of the main body and the second flange is about 90°.

In some embodiments, the first flange extends radially away from themain body parallel to the second flange. In some embodiments, the firstflange and the second flange extend radially away from the main body indirections converging toward one another such that an angle between theradially extending flanges is less than about 10°. In some embodiments,the first flange and the second flange extend radially away from themain body in directions diverging away from one another such that anangle between the radially extending flanges is less than about 10°.

In some embodiments, a method of implanting a prosthetic apparatus atthe native mitral valve region of a heart comprises delivering theprosthetic apparatus to the native mitral valve region within a deliveryapparatus, and deploying the prosthetic apparatus from the deliveryapparatus, wherein the prosthetic apparatus comprises a main body, afirst flange coupled to the main body and extending radially away fromthe main body perpendicular to a side of the main body, and a secondflange coupled to the main body and extending radially away from themain body perpendicular to the side of the main body, and whereindeploying the prosthetic apparatus from the delivery apparatus allowsthe prosthetic apparatus to radially expand, such that a distancebetween the first flange and the second flange decreases and the firstflange and the second flange pinch a native mitral valve annulus betweenthem.

In some embodiments, the prosthetic apparatus has an inlet end and anoutlet end, and the first flange and the second flange are coupled tothe main body at locations located closer to the inlet end than to theoutlet end of the prosthetic apparatus. In some embodiments, theprosthetic apparatus has an inlet end and an outlet end, and the firstflange and the second flange are coupled to the main body at locationslocated closer to the outlet end than to the inlet end of the prostheticapparatus. In some embodiments, the main body has a first end and asecond end, and comprises a network of struts interconnected at aplurality of nodes to form a plurality of open cells; the first flangeis coupled to first nodes of the main body at the first end of the mainbody; and the second flange is coupled to second nodes of the main body,which are displaced toward the second end of the main body from thefirst end of the main body by the smallest increment available. In someembodiments, the main body has a first end and a second end, andcomprises a network of struts interconnected at a plurality of nodes toform a plurality of open cells; the first flange is coupled to firstnodes of the main body at the first end of the main body; and the secondflange is coupled to second nodes of the main body, the second nodesbeing the closest nodes in the network of struts to the first nodes. Insome embodiments, the main body has a first end and a second end, andcomprises a network of struts interconnected at a plurality of nodes toform a plurality of open cells; the first flange is coupled to firstnodes of the main body at the first end of the main body; and the secondflange is coupled to second nodes of the main body, the first nodes andthe second nodes being situated in a single circumferential row of opencells.

The foregoing and other objects, features, and advantages of theinvention will become more apparent from the following detaileddescription, which proceeds with reference to the accompanying figures.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates an exemplary prosthetic heart valve frame.

FIG. 2 illustrates the exemplary prosthetic heart valve frame of FIG. 1from a different angle.

FIG. 3 illustrates the exemplary prosthetic heart valve frame of FIG. 1from a ventricular end view.

FIG. 4 illustrates an exemplary prosthetic heart valve frame, in anexpanded configuration, from a side view.

FIG. 5 illustrates the exemplary prosthetic heart valve frame of FIG. 4,in a compressed configuration, from a side view.

FIG. 6 illustrates the exemplary prosthetic heart valve frame of FIG. 4,in an expanded configuration, from an end view.

FIG. 7 illustrates the exemplary prosthetic heart valve frame of FIG. 4,in a compressed configuration, from an end view.

FIG. 8 illustrates an outer sheath of an exemplary delivery system.

FIG. 9 illustrates a slotted sheath of an exemplary delivery system.

FIG. 10 illustrates a nosecone of an exemplary delivery system.

FIG. 11 illustrates an inner pusher shaft of an exemplary deliverysystem.

FIGS. 12A, 13A, 14A, 15A, and 16A illustrate an exemplary deliverysequence of an exemplary prosthetic heart valve frame using the deliverysystem of FIGS. 8-11.

FIGS. 12B, 13B, 14B, 15B, and 16B illustrate an exemplary deliverysequence of an exemplary prosthetic heart valve frame.

FIG. 17A illustrates a slotted sheath having a retaining element.

FIGS. 17B-17C illustrate an alternative retaining element.

FIGS. 17D-17E illustrate another alternative retaining element.

FIG. 18 illustrates a transventricular delivery approach.

FIG. 19 illustrates a transfemoral delivery approach.

FIG. 20 illustrates a transeptal delivery approach.

FIG. 21 illustrates a transatrial delivery approach.

DETAILED DESCRIPTION

Frames for Use in Prosthetic Valves

The frames described herein can be used to provide structure toprosthetic valves designed to be implanted within the vasculature of apatient. The frames described herein can be particularly advantageousfor use in prosthetic valves to be implanted within a patient's nativemitral valve, but can be used in prosthetic valves to be implanted invarious other portions of a patient's vasculature (e.g., another nativevalve of the heart, or various other ducts or orifices of the patient'sbody). When implanted, the frames described herein can providestructural support to a leaflet structure and/or other components of aprosthetic valve such that the prosthetic valve can function as areplacement for a native valve, allowing fluid to flow in one directionthrough the prosthetic valve from an inlet end to an outlet end, but notin the other or opposite direction from the outlet end to the inlet end.Details of various prosthetic valve components can be found in U.S. Pat.Nos. 6,730,118, 7,393,360, 7,510,575, and 7,993,394, which are herebyincorporated herein by reference in their entireties.

The frames described herein can be configured to be radially collapsibleto a collapsed or crimped state for introduction into the body on adelivery catheter and radially expandable to an expanded state forimplanting a prosthetic valve at a desired location in the body (e.g.,the native mitral valve). The frames can be made of aplastically-expandable material that permits crimping of the prostheticvalve to a smaller profile for delivery and expansion of the prostheticvalve using an expansion device such as the balloon of a ballooncatheter. Suitable plastically-expandable materials that can be used toform the frames include, without limitation, stainless steel,cobalt-chromium, nickel-based alloy (e.g., a nickel-cobalt-chromiumalloy), polymers, or combinations thereof. In particular embodiments,the frames are made of a nickel-cobalt-chromium-molybdenum alloy, suchas MP35N® alloy (SPS Technologies), which is equivalent to UNS R30035(covered by ASTM F562-02). MP35N® alloy/UNS R30035 comprises 35% nickel,35% cobalt, 20% chromium, and 10% molybdenum, by weight. It has beenfound that the use of MP35N® alloy to form a frame provides superiorstructural results over stainless steel. In particular, when MP35N®alloy is used as the frame material, less material is needed to achievethe same or better performance in radial and crush force resistance,fatigue resistances, and corrosion resistance. Moreover, since lessmaterial is required, the crimped profile of the frames can be reduced,thereby providing a lower profile prosthetic valve assembly forpercutaneous delivery to the treatment location in the patient's body.

Alternatively, any of the frames described herein can be a so-calledself-expanding frame wherein the frame is made of a self-expandingmaterial such as nitinol. A prosthetic valve incorporating aself-expanding frame can be crimped to a smaller profile and held in thecrimped state with a restraining device such as a sheath covering theprosthetic valve. When the prosthetic valve is positioned at or near atarget site within the patient's vasculature, the restraining device canbe removed to allow the prosthetic valve to self-expand to its expanded,functional size.

FIGS. 1-3 illustrate an exemplary prosthetic heart valve frame 100.Frame 100 includes a main body 102, a first flange 104, and a secondflange 106. The main body 102 can be formed from a plurality of struts108 coupled to one another at a plurality of nodes 110 to form a networkof struts 108 defining a plurality of open cells 112. The main body 102can have a first end portion 118, which can be referred to as an atrialend portion 118 or an inlet end portion 118, and a second end portion120, which can be referred to as a ventricular end portion 120 or anoutlet end portion 120, and can include three commissure attachmentposts 114, each including a plurality of openings 116 to allow othercomponents such as prosthetic valve leaflets to be coupled (e.g.,stitched) to the frame 100. Suitable components and methods for couplingthe other components to the frame 100 are known in the art. The firstflange 104 can be referred to as the atrial flange 104, and the secondflange 106 can be referred to as the ventricular flange 106, due totheir relative locations with respect to one another and the left atriumand the left ventricle when the frame is implanted in the native mitralvalve.

In an alternative embodiment, the first end portion 118 is aventricular, outlet end portion, the second end portion 120 is anatrial, inlet end portion, the first flange 104 is a ventricular flange,and the second flange 106 is an atrial flange 106.

The main body 102 and flanges 104, 106 have generally circular shapes inthe illustrated embodiment. In alternative embodiments, the main bodyand flanges of a prosthetic mitral valve frame can have non-circularshapes, for example, to accommodate the non-circular shape of the nativemitral valve annulus. In certain embodiments, the main body and flangesof a prosthetic mitral valve frame can be generally oval-shaped,ellipse-shaped, kidney-shaped, or D-shaped.

In the illustrated embodiment, the atrial flange 104 and the ventricularflange 106 are coupled to the main body 102 at respective locationslocated nearer to the atrial end 118 of the main body 102 than to theventricular end 120. More specifically, the atrial flange 104 is coupledto the nodes 110A of the main body 102 which are closest to the atrialend portion 118 of the main body 102. The ventricular flange 106 iscoupled to the nodes 110B of the main body 102 which are displacedtoward the ventricular end 120 of the main body 102 from the atrialflange 104 by the smallest increment available. That is, the nodes 110Bare the closest nodes 110 in the network of struts 108 to the nodes110A. In other embodiments, the nodes 110B are not the closest nodes 110to the nodes 110A, for example, the second closest or third closestnodes, or another set of nodes. In alternative embodiments, the atrialand ventricular flanges 104, 106 can be coupled to the main body 102 atany suitable locations, which need not be at nodes 110. For example, oneor both of the flanges 104, 106 can be coupled to the mid-points ofstruts 108 of the main body 102 rather than to nodes 110.

As shown in FIG. 3, in the illustrated configuration, the atrial flange104 comprises nine atrial protrusions 122, and the ventricular flange106 comprises nine ventricular protrusions 124. In alternativeembodiments, the atrial flange can comprise more than or fewer than nineatrial protrusions and the ventricular flange can comprise more than orfewer than nine ventricular protrusions. In some embodiments, the atrialand/or the ventricular flange can include at least three, at least four,at least five, at least six, at least seven, at least eight, at leastnine, at least ten, at least twelve, at least fifteen, or at leasttwenty protrusions. In the illustrated embodiment, the atrialprotrusions 122 are slightly larger than the ventricular protrusions124. In alternative embodiments, the protrusions 122, 124 can be aboutthe same size, or the ventricular protrusions 124 can be larger than theatrial protrusions 122. In the illustrated embodiment, the atrialprotrusions 122 are angularly offset from the ventricular protrusions124. In alternative embodiments, the protrusions 122, 124 can beangularly aligned with one another. Other embodiments include at leastone set of protrusions 122, 124 that is angularly aligned and at leastone set of protrusions 122, 124 that is not angularly aligned. Eachatrial protrusion 122 comprises a first radial strut 126 coupled to anode 110A (FIG. 1) and extending radially outward from the main body102, and a second radial strut 128 coupled to a node 110A and extendingradially outward from the main body 102. Each protrusion 122 furthercomprises a first angled strut 130 coupled to the first radial strut 126at a node 132, and a second angled strut 134 coupled to the secondradial strut 128 at a node 136. Each first angled strut 130 is coupledto each second angled strut 134 at a respective radial node 138.

Each ventricular protrusion 124 similarly comprises a first radial strut140 coupled to a node 110B (FIG. 1) and extending radially outward fromthe main body 102, and a second radial strut 142 coupled to a node 110Band extending radially outward from the main body 102. Each protrusion124 further comprises a first angled strut 144 coupled to the firstradial strut 140 at a node 146, and a second angled strut 148 coupled tothe second radial strut 142 at a node 150. Each first angled strut 144is coupled to each second angled strut 148 at a respective radial node152. Thus, the protrusions 122 and 124 each comprise a series of strutsforming a loop coupled to and extending radially away from the main body102.

The nodes 138 and 152 of the protrusions 122 and 124, respectively,comprise generally U-shaped crown structures or crown portions. Crownstructures can each include a horizontal portion extending between andconnecting the adjacent ends of the struts such that a gap is definedbetween the adjacent ends and the crown structure connects the adjacentends at a location offset from the struts' natural point ofintersection. The nodes 132 and 136, and 146 and 150 of the protrusions122 and 124, respectively, also comprise stepped portions that areshaped to connect the adjacent ends of the struts at a location offsetfrom the struts' natural point of intersection. Crown structures andstepped portions, both individually and in combination, cansignificantly reduce strain on the frame 100 during crimping andexpanding of the frame 100. Further details regarding crown structuresare available in U.S. Pat. No. 7,993,394.

Also shown in FIG. 3 are three prosthetic valve leaflets 154 coupled tothe frame 100 at the commissure attachment posts 114. FIG. 3 alsoillustrates that a prosthetic valve can include a first fabric layer 156covering the ventricular protrusions 124 and a second fabric layer 158covering the atrial protrusions 122, as well as a third fabric layer 160covering the main body 102 of the frame 100. The fabric layers canimprove the seal formed between the prosthetic valve and the surroundingnative tissues of a native heart valve when the prosthetic valve isimplanted. The fabric layers 156, 158, 160 can also reduce trauma tonative tissues caused by the implantation of the prosthetic valve, andcan help to promote tissue ingrowth into the prosthetic valve. Thefabric layers 156, 158, 160 can be made from any of various suitablefabrics, including polyethylene terephthalate (PET).

In the illustrated embodiment, the commissure attachment posts 114 arecoupled to radial struts 140, 142 of ventricular protrusions 124, butnot to radial struts 126, 128 of atrial protrusions 122. Also in theillustrated embodiment, the commissure attachment posts 114 areangularly aligned about a central longitudinal axis of the frame 100with radial nodes 138 of atrial protrusions 122, but not with radialnodes 152 of ventricular protrusions 124. In alternative embodiments,the commissure attachment posts 114 can be coupled to radial struts 126,128 of atrial protrusions 122, and angularly aligned about the centrallongitudinal axis with radial nodes 152 of ventricular protrusions 124.

As explained above, a prosthetic valve frame can be radially collapsibleto a collapsed or crimped state for introduction into the body, andradially expandable to an expanded state for implantation at a desiredlocation in the body. FIGS. 4-7 illustrate a frame 200 from side views(FIGS. 4 and 5) and atrial end views (FIGS. 6 and 7) with a main body202 of the frame 200 in expanded (FIGS. 4 and 6) and crimped (FIGS. 5and 7) configurations. Frame 200 includes main body 202, an atrialflange 204, and a ventricular flange 206. The main body 202 has adiameter D₁ in the expanded configuration and a diameter D₂ in thecrimped configuration. The flanges 204, 206 have a diameter or width W₁in the expanded configuration of the main body and a diameter or widthW₂ in the crimped configuration of the main body. In the illustratedembodiments, the flanges 204, 206 have the same widths W₁ and W₂; asdiscussed above, in other embodiments, the flanges 204, 206 havedifferent widths. The flanges 204, 206 are spaced apart from one anotherby a spacing S₁ in the expanded configuration and by a spacing S₂ in thecrimped configuration.

In some embodiments, S₁ can be between about 2 mm and about 20 mm, withabout 6 mm being one possible specific dimension. In some embodiments,S₂ can be between about 4 mm and about 30 mm, with about 12 mm being onepossible specific dimension. In some embodiments, W₁ can be betweenabout 30 mm and about 75 mm, with about 55 mm being one possiblespecific dimension. In some embodiments, W₂ can be between about 10 mmand about 60 mm, with about 45 mm being one possible specific dimension.In some embodiments, D₁ can be between about 25 mm and about 50 mm, withabout 29 mm being one possible specific dimension. In some embodiments,D₂ can be between about 4 mm and about 10 mm, with about 6.5 mm beingone possible specific dimension.

As illustrated in FIGS. 4-7, as the main body of the frame 200 collapsesfrom the expanded configuration to the crimped configuration, thediameter of the main body 202 decreases significantly (from D₁ to D₂),the width of the flanges 204, 206 decreases (from W₁ to W₂), and thespacing between the flanges 204, 206 increases (from S₁ to S₂). Further,as the main body of the frame 200 collapses from the expandedconfiguration to the crimped configuration, the protrusions making upthe flanges 204, 206 are compressed angularly such that they transitionfrom a series of relatively wide-and-short radially-extendingprotrusions to a series of relatively narrow-and-long radially-extendingprotrusions. As shown in FIGS. 4 and 5, an angle between the main body202 and the radially extending flanges 204, 206 can be about 90°. Inalternative embodiments, an angle between the side of the main body 202and the radially extending flanges 204, 206, can be between about 80°and about 100°, or between about 70° and about 110°, or between about60° and about 120°.

As shown in FIGS. 4 and 5, the radially extending flanges 204, 206 canextend away from the main body 202 in directions generally parallel toone another. In alternative embodiments, the radially extending flanges204, 206 can extend away from the main body 202 in directions convergingtoward one another such that an angle between the radially extendingflanges is less than about 1°, or less than about 2°, or less than about5°, or less than about 10°, or less than about 15°, or less than about20°, or less than about 25°, or less than about 30°. In otherembodiments, the radially extending flanges 204, 206 can extend awayfrom the main body 202 in directions diverging away from one anothersuch that an angle between the radially extending flanges is less thanabout 1°, or less than about 2°, or less than about 5°, or less thanabout 10°, or less than about 15°, or less than about 20°, or less thanabout 25°, or less than about 30°.

The frame 200 can be used as the frame of a prosthetic valve to beimplanted at the native mitral valve of a human heart. As shown in FIG.18, the native mitral valve 300 of the human heart connects the leftatrium 302 to the left ventricle 304. The native mitral valve 300includes a native mitral valve annulus 308, which is an annular portionof native tissue surrounding the native mitral valve orifice, and a pairof leaflets 306 coupled to the native mitral valve annulus 308 andextending ventricularly from the annulus 308 into the left ventricle304. As described in more detail below, in one exemplary method, aprosthetic valve including the frame 200 can be compressed to a crimpedconfiguration, loaded into a delivery system, and introduced into theregion of the native mitral valve of a patient's heart. With the framein the crimped configuration and thus the spacing between the atrial andventricular flanges 204, 206 maximized, the prosthetic valve can bepositioned so that the native mitral valve annulus 308 is situatedbetween the flanges 204, 206. The prosthetic valve can then be expandedto the expanded configuration such that the spacing between the flanges204, 206 is reduced to less than the native thickness of the nativemitral valve annulus 308. The flanges 204, 206 can then retain theprosthetic valve in place in the native mitral valve by compressing orpinching the annulus 308. By pinching the native mitral valve annulus,the flanges 204, 206 can also maintain a continuous seal between thenative tissue and the prosthetic valve around the exterior of theprosthetic valve, thereby preventing blood from flowing between theoutside of the prosthetic valve and the surrounding annulus, andallowing the prosthetic valve to control the flow of blood between theleft atrium and the left ventricle.

This method takes advantage of the relative movement of the nodes of theprosthetic valve frame in a direction aligned with the centrallongitudinal axis of the prosthetic valve. In particular, as aprosthetic valve frame such as frame 100 or frame 200 is radiallyexpanded, nodes aligned with one another along an axis parallel to thecentral longitudinal axis move toward one another. Thus, by coupling apair of flanges such as flanges 104 and 106, or flanges 204 and 206 tonodes spaced apart from each other axially, the flanges can be made toapproach one another as the prosthetic valve expands.

Delivery Systems and Methods

FIGS. 8-11 illustrate components of an exemplary delivery system 400(FIGS. 12A-16A) which can be used to deliver a prosthetic valveincluding a frame such as frame 100 or frame 200 to a native heartvalve. FIG. 8 illustrates an outer sheath 402 of the delivery system400. Outer sheath 402 is a hollow sheath which surrounds the remainingcomponents of the delivery system 400 and the prosthetic valve beingdelivered. FIG. 9 illustrates a slotted sheath 404 of the deliverysystem 400. Slotted sheath 404 includes a plurality of distal extensions406 separated by a plurality of distal slots 408. In some embodiments,the slotted sheath 404 can include at least three, at least four, atleast five, at least six, at least seven, at least eight, at least nine,at least ten, at least twelve, at least fifteen, or at least twentyslots 408. In some embodiments, the number of slots 408 in the slottedsheath 404 can correspond to a number of atrial protrusions, and/or anumber of ventricular protrusions in a frame of a prosthetic valve,and/or a sum of the number of atrial protrusions and the number ofventricular protrusions. Slotted sheath 404 has an outside diameterslightly smaller than the inside diameter of the outer sheath 402 sothat the slotted sheath 404 can fit within the outer sheath 402.

FIG. 10 illustrates a nosecone 410 coupled to an inner shaft 412 of thedelivery system 400. The nosecone is hollow and includes an inner recess414. The nosecone 410 can have an outer diameter matching that of theouter sheath 402, and the recess 414 can have a diameter slightly largerthan the outer diameter of the slotted sheath 404 so that a distal endportion of the slotted sheath 404 can fit within the recess 414. FIG. 11illustrates an inner pusher shaft 416 of the delivery system 400. Thepusher shaft 416 can have an outside diameter smaller than an insidediameter of the slotted sheath 404 so that the pusher shaft 416 can fitwithin the slotted sheath 404. The pusher shaft 416 can also have aninternal lumen 418 through which the inner shaft 412 can fit. Whenassembled, the delivery system 400 can include, from center to exterior,the inner shaft 412, the pusher shaft 416, the slotted sheath 404, andthe outer sheath 402.

FIGS. 12A, 13A, 14A, 15A, and 16A illustrate an exemplary deliverysequence of a radially self-expanding prosthetic heart valve frame 420from delivery system 400. FIG. 12A illustrates the delivery system 400in a closed, delivery configuration in which the frame 420 is retainedwithin the system 400 (the prosthetic valve can be retained in aradially compressed state within an annular space defined between theslotted sheath 404 and the inner shaft 412 and the nosecone 410). Asshown in FIG. 13A, the outer sheath 402 can be retracted proximally toexpose the distal extensions 406 of the slotted sheath 404. As shown inFIG. 14A, the inner shaft 412 and nosecone 410 can be extended distallyto expose the distal end portion of the slotted sheath 404.

As shown in FIG. 15A, the inner shaft 412 and nosecone 410 can befurther extended distally to provide sufficient space for the prostheticvalve frame 420 to be pushed out of the slotted sheath 404. The pushershaft 416 can then be extended distally while the slotted sheath 404 isretracted proximally so that the prosthetic valve frame 420 is pusheddistally through the slotted sheath 404 until the prosthetic valve frame420 becomes partially exposed and begins to radially self-expand. Asshown in FIG. 16A, the inner shaft 412 and nosecone 410 can be furtherextended distally to provide additional space for the prosthetic valveframe 420 to be pushed out of the slotted sheath 404. The pusher shaft416 can then be further extended distally while the slotted sheath 404is further retracted proximally so that the prosthetic valve frame 420is pushed distally through the slotted sheath 404 until the prostheticvalve frame 420 becomes completely exposed from the system 400 andradially self-expands to a fully expanded configuration.

In an alternative embodiment, the protrusions of a flange of aprosthetic valve frame, such as the protrusions of flanges 104, 106,204, or 206, or protrusions 422 of prosthetic valve frame 420, can fitwithin or extend through the distal slots 408 of the slotted sheath 404.As described above, as prosthetic valve frames 100, 200, 420 arecompressed to a crimped configuration, the respective protrusions arecompressed angularly such that they transition from a series ofrelatively wide and short, radially-extending protrusions to a series ofrelatively narrow and long, radially-extending protrusions. Thus, theprotrusions can be configured to fit within the distal slots 408 when aframe is in the crimped configuration. In this embodiment, loading aprosthetic valve into a delivery system can include crimping theprosthetic valve to a compressed configuration, inserting the compressedprosthetic valve into the slotted sheath 404 such that the angularlycompressed protrusions fit within the distal slots 408 of the slottedsheath 404, and then adjusting the protrusions so they lie flat againstthe outside of the slotted sheath 404, or so they lie flat within theslots 408 and against the outside of the main body of the prostheticvalve, so the prosthetic valve and slotted sheath 404 can be containedwithin the outer sheath 402 and recess 414 of the nosecone 410. Theprotrusions of one of the flanges can be contained within the nosecone410, and the protrusions of the other flange can be contained within theouter sheath 402. Adjusting the protrusions so they lie flat against theoutside of the slotted sheath, or so they lie flat within the slots 408and against the outside of the main body of the prosthetic valve, caninclude bending the protrusions of the atrial flange so they pointeither toward or away from the protrusions of the ventricular flange,and bending the protrusions of the ventricular flange so they pointeither toward or away from the protrusions of the atrial flange.

FIGS. 12B, 13B, 14B, 15B, and 16B illustrate an exemplary deliverysequence of the prosthetic heart valve frame 420 from the deliverysystem 400. FIG. 12B shows the frame 420 in a compressed configurationwith protrusions 422A and 422B lying flat against a main body 424 of theframe 420, such that the frame 420 can be situated within the deliverysystem 400 in the configuration shown in FIG. 12A. FIG. 13B shows themain body 424 of the frame 420 in a compressed configuration withprotrusions 422B lying flat against the main body 424 of the frame 420,and with the protrusions 422A extending radially outward from the mainbody 424 of the frame 420, such that the frame 420 can be situatedwithin the delivery system 400 and the protrusions 422A can extendthrough the slots 408 of the delivery system 400 in the configurationshown in FIG. 13A. FIG. 14B shows the main body 424 of the frame 420 ina compressed configuration with protrusions 422A and the protrusions422B extending radially outward from the main body 424 of the frame 420,such that the frame 420 can be situated within the delivery system 400and the protrusions 422A, 422B can extend through the slots 408 of thedelivery system 400 in the configuration shown in FIG. 14A.

FIG. 15B shows the main body 424 of the frame 420 in a partiallyexpanded configuration in which a first end 426 of the frame 420 is in acompressed configuration and a second end 428 of the frame 420 is in anexpanded configuration, such that the frame 420 can be situated withinthe delivery system 400 in the configuration shown in FIG. 15A. FIG. 16Bshows the main body 424 of the frame 420 in a fully expandedconfiguration in which the first end 426 and the second end 428 are inexpanded configurations, such that the frame 420 can be situated on thedelivery system 400 in the configuration shown in FIG. 16A.

FIG. 17A illustrates an exposed distal end portion of a slotted sheath500 having a plurality of distal extensions 506, an outer sheath 502,and a retaining element 504. Small holes extend through the distalextensions 506 so that the retaining element 504, which can be wire,string, and/or suture, can be threaded through the holes. In some cases,the retaining element 504 can extend from a proximal end portion of theouter sheath 502, where it can be controlled by a physician, along thelength of the outer sheath 502, and into a first hole through a firstdistal extension 506A. The retaining element 504 can then be threadedthrough the holes of successive distal extensions 506 in a coiled orhelical configuration until it extends out of a final hole through afinal distal extension 506B. In an alternative embodiment, a retainingelement can extend into the first hole of the first distal extension506A, extend through the holes of successive distal extensions 506 in aplurality of circles, and extend out of the final hole of the finaldistal extension 506B. In some cases, a tension force can be applied tothe retaining element 504. The retaining element 504 can help torestrain the distal extensions 506 against radial expansion from theexpansion force of a prosthetic valve retained within the extensions506.

FIGS. 17B-17C illustrate an alternative retaining element 510 which canbe used in combination with the outer sheath 502, slotted sheath 500,and distal extensions 506, either in place of, or in addition to, theretaining element 504. Retaining element 510 includes a sheath 511having a distal end portion comprising a plurality of teeth 512 and aplurality of gaps 514 between the teeth 512. In use in a delivery systemincluding outer sheath 502, slotted sheath 500, and distal extensions506, as shown in FIG. 17C, the retaining element 510 can be situatedbetween the outer sheath 502 and the slotted sheath 500. The teeth 512can have a one-to-one correspondence with the distal extensions 506, andeach tooth 512 can be rotationally offset with respect to a respectivedistal extension 506 so as to form a protrusion-receiving opening 516.

Loading a prosthetic valve including a frame such as frame 100, frame200, or frame 420 into the delivery system can proceed according tosimilar methods, but is described herein with reference to frame 420 forconvenience. Loading a prosthetic valve including frame 420 into thedelivery system can include crimping the prosthetic valve to acompressed configuration, in which the protrusions 422A, 422B of theframe are angularly compressed, as described above. The compressedprosthetic valve can then be inserted into the slotted sheath 500 suchthat the angularly compressed protrusions 422A, 422B fit within slots507 between the extensions 506, such that the protrusions 422A areproximal to the protrusions 422B, and such that the proximal set ofangularly compressed protrusions 422A extend through the slots 507 andthe openings 516. The retaining element 510 can then be rotated in theopposite direction shown by arrow 518, so as to pinch the proximal setof angularly compressed protrusions 422A between the teeth 512 and theextensions 506. The angularly compressed protrusions 422A and 422B canthen be adjusted so they lie flat against the outside of the slottedsheath 500, or so they lie flat within the slots 507 and against theoutside of the main body 424 of the prosthetic valve frame 420. Theouter sheath 502 can then be actuated to move distally with respect tothe slotted sheath 500 to enclose the slotted sheath 500, the retainingelement 510, and the prosthetic valve.

Deployment of the prosthetic valve from the delivery system cangenerally progress as described above with reference to FIGS. 12A-16Aand 12B-16B, and can include proximally retracting the outer sheath 502with respect to the slotted sheath 500 to reveal the slotted sheath 500and the prosthetic valve, such that the angularly compressed protrusions422A, 422B extend radially outward through the slots 507 between theextensions 506 and the proximal angularly compressed protrusions 422Aextend radially through the openings 516. A pusher shaft of the deliverysystem can then be actuated to push the prosthetic valve distallythrough the slotted sheath 500, and the retaining element 510 can beactuated to move distally over the slotted sheath 500 with theprosthetic valve. In this way, the proximal set of angularly compressedprotrusions 422A can remain pinched between the teeth 512 and theextensions 506 as the prosthetic valve is deployed. When the prostheticvalve approaches the distal end of the extensions 506, the retainingelement 510 can be rotated, for example, in the direction shown by thearrow 518 (FIG. 17C), such that it no longer pinches or holds (e.g., itreleases) the proximal protrusions 422A. In some cases, releasing theproximal protrusions 422A in this way allows the proximal protrusions422A to more fully radially extend outward through the openings 516.Thus, while the distal and proximal protrusions 422B, 422A are deployed,the main body 424 remains in a radially compressed state within theslotted sheath 500. In some cases, the retaining element 510 can then beretracted proximally with respect to the prosthetic valve to allow acontrolled expansion of the prosthetic valve and a controlled release ofthe prosthetic valve from the extensions 506. As the main body 424 isdeployed, the distal and proximal protrusions 422B, 422A can slideaxially in the distal direction through the distal openings 509 of theslots 507.

The retaining element 510 can provide substantial benefits to thedelivery system. For example, the retaining element 510 can help torestrain the distal extensions 506 against radial expansion from theexpansion force of the prosthetic valve retained within the extensions506. In particular, as the prosthetic valve moves distally through theextensions 506, the extensions 506 can tend to splay farther and fartherapart. The retaining element can help to reduce this effect bymaintaining a ring of material (e.g., the distal end portion of thesheath 511) in proximity to the proximal end of the prosthetic valve asthe prosthetic valve moves through the extensions 506. This can providean operator with a greater degree of control over the delivery systemand the deployment of the prosthetic valve therefrom.

FIGS. 17D-17E illustrate an alternative retaining element 520 which canbe used in combination with the outer sheath 502, slotted sheath 500,and distal extensions 506, either in place of, or in addition to, theretaining element 504. Retaining element 520 includes a sheath 521having a distal end portion comprising a plurality of L-shaped teeth 522and gaps 524 between the teeth 522. The L-shaped teeth 522 can include alongitudinal portion 522A, a corner portion 522B, and a circumferentialportion 522C. In use in a delivery system including outer sheath 502,slotted sheath 500, and distal extensions 506, as shown in FIG. 17E, theretaining element 520 can be situated between the outer sheath 502 andthe slotted sheath 500. The teeth 522 can have a one-to-onecorrespondence with the distal extensions 506, and each tooth 522 can berotationally offset with respect to a respective distal extension 506 soas to form an enclosed, protrusion-receiving opening 526.

Loading a prosthetic valve including a frame such as frame 100 or frame200 into the delivery system can generally progress as described above,and such that a proximal set of angularly compressed protrusions 422A ofa prosthetic valve frame fit within the openings 526. The retainingelement 520 can be rotated in the opposite direction shown by arrow 528so as to capture the proximal set of angularly compressed protrusions422A in the enclosed openings 526. Deployment of the prosthetic valvefrom the delivery system can generally progress as described above. Whenthe prosthetic valve approaches the distal end of the extensions 506,the retaining element 520 can be rotated in the direction shown by thearrow 528 such that it no longer captures or constrains (e.g., itreleases) the proximal protrusions 422A.

The retaining element 520 can provide substantial benefits to thedelivery system, as described above with regard to retaining element510. In some cases, the retaining element 510 can be easier tomanufacture than the retaining element 520. In some cases, the retainingelement 520 provides better performance than the retaining element 510because the teeth form enclosed openings and capture the proximalprotrusions rather than pinching the proximal protrusions.

Delivery Approaches

FIGS. 18-21 illustrate delivery approaches by which the delivery system400 can be used to deliver a prosthetic valve to a patient's nativemitral valve. FIGS. 18 and 19 illustrate that delivery from theventricular side of the native mitral annulus 308 can be accomplishedvia transventricular and transfemoral approaches, respectively. Todeliver a prosthetic valve including frame 100 to a patient's nativemitral valve from the ventricular side of the native mitral annulus 308,the prosthetic valve can be loaded into the delivery system 400 so thatthe atrial end portion 118 of the frame is positioned nearer to thedistal end of the delivery system 400 than the ventricular end portion120 of the frame is. In this embodiment, when the prosthetic valve isdelivered to and deployed within the native mitral valve, the atrial endportion 118 is situated within the left atrium 302 and the ventricularend portion 120 is situated within the left ventricle 304.

In some embodiments, a prosthetic valve including protrusions fittedwithin the distal slots of a slotted sheath such as slotted sheath 404can be deployed from a delivery system incorporating a retaining elementsuch as retaining element 504, retaining element 510, or retainingelement 520, approaching the native mitral valve from the ventricularside of the native mitral valve annulus 308. The prosthetic valve can becompressed to a crimped configuration and loaded into the deliverysystem such that the protrusions of an atrial flange are retained withinthe nosecone 410 of the delivery system and the protrusions of aventricular flange are retained within the outer sheath 402 of thedelivery system. The delivery system can then advance the prostheticvalve to the native mitral valve from the ventricular side of the nativemitral valve annulus via either a transventricular or a transfemoralapproach. In the transventricular approach, the delivery systemdesirably is inserted through a surgical incision made on the bare spoton the lower anterior ventricle wall.

As shown in FIG. 18, the outer sheath 402 can then be retracted toexpose the protrusions 124 of the ventricular flange 106 within the leftventricle 304, and the delivery system can be advanced until theventricular flange 106 is in contact with the native valve leaflets 306and adjacent the ventricular side of the native mitral valve annulus308. The nosecone 410 can then be extended to deploy the protrusions 122of the atrial flange 104 into the left atrium 302, across the nativemitral valve annulus 308 from the protrusions of the ventricular flange106. In cases where retaining element 504 is used, any tension forceapplied to the retaining element 504 can be removed, and the retainingelement 504 can be actuated (e.g., pulled proximally) so that theretaining element 504 migrates through the holes in the distalextensions 406 of the delivery system until the retaining element 504 isno longer situated within the holes. A pusher shaft 416 of the deliverysystem can then be extended distally while the slotted sheath 404 isretracted proximally so that the prosthetic valve is deployed from thedelivery system and allowed to radially expand within the native mitralvalve. In some cases, retaining element 510 or retaining element 520 canbe used to help restrain the distal extensions of the slotted sheath 404against radial expansion during this step. As the prosthetic valveradially expands within the native mitral valve, the spacing between theatrial and ventricular flanges 122, 124, respectively, decreases andthey compress the native mitral valve annulus 308. As the prostheticvalve radially expands, the protrusions also angularly expand to theirexpanded configuration. The delivery system can then be removed from thepatient's vasculature, leaving the prosthetic valve in place in thenative mitral valve.

FIGS. 20 and 21 illustrate that delivery from the atrial side of thenative mitral annulus 308 can be accomplished via transeptal ortransatrial approaches. To deliver a prosthetic valve including frame100 to a patient's native mitral valve from the atrial side of thenative mitral annulus 308, the prosthetic valve can be loaded into thedelivery system 400 so that the ventricular end portion 120 of the frameis positioned nearer to the distal end of the delivery system 400 thanthe atrial end portion 118 of the frame is. In this embodiment, when theprosthetic valve is delivered to and deployed within the native mitralvalve, the atrial end portion 118 is situated within the left atrium 302and the ventricular end portion 120 is situated within the leftventricle 304.

In some embodiments, a prosthetic valve including protrusions fittedwithin the distal slots of a slotted sheath such as slotted sheath 404can be deployed from a delivery system incorporating a retaining elementsuch as retaining element 504, retaining element 510, or retainingelement 520, approaching the native mitral valve from the atrial side ofthe native mitral valve annulus 308. The prosthetic valve can becompressed to a crimped configuration and loaded into the deliverysystem such that the protrusions 124 of a ventricular flange 106 areretained within the nosecone 410 of the delivery system and theprotrusions 122 of an atrial flange 104 are retained within the outersheath 402 of the delivery system. The delivery system can then advancethe prosthetic valve to the native mitral valve from the atrial side ofthe native mitral valve annulus via either a transeptal or a transatrialapproach.

The nosecone 410 can then be extended to deploy the protrusions 124 ofthe ventricular flange 106 within the left ventricle 304, and thedelivery system can be retracted until the ventricular flange 106 is incontact with the native valve leaflets 306 and adjacent the ventricularside of the native mitral valve annulus 308. The outer sheath 402 canthen be retracted to deploy the protrusions 122 of the atrial flange 104into the left atrium 302, across the native mitral valve annulus 308from the protrusions of the ventricular flange 106. In cases whereretaining element 504 (FIG. 17A) is used, any tensile force applied tothe retaining element 504 can be removed, and the retaining element 504can be actuated so that the retaining element 504 migrates through theholes in the distal extensions 406 of the delivery system until theretaining element 504 is no longer situated within the holes. The outersheath 402 and slotted sheath 404 can then be retracted while a pushershaft 416 of the delivery system is held stationary so that theprosthetic valve is exposed from the delivery system and allowed toradially expand within the native mitral valve. In some cases, retainingelement 510 or retaining element 520 can be used to help restrain thedistal extensions of the slotted sheath 404 against radial expansionduring this step. As the prosthetic valve radially expands within thenative mitral valve, the spacing between the atrial and ventricularflanges 104, 106 decreases and they compress the native mitral valveannulus 308. As the prosthetic valve radially expands, the protrusionsalso angularly expand to their expanded configuration. The deliverysystem can then be removed from the patient's vasculature, leaving theprosthetic valve in place in the native mitral valve.

In embodiments in which protrusions of the frame of a prosthetic valveextend through the distal slots 408 of the slotted sheath 404, theangular compression of the protrusions makes them narrower, and thuseasier to navigate to the native mitral valve. For example, the nativemitral valve can include chordae tendineae 310 (FIG. 18), which tetherthe leaflets 306 to the walls of the left ventricle 304. The chordaetendineae 310 can interfere with delivery of a prosthetic valve to thenative mitral valve (particularly from the ventricular side of thenative mitral annulus 308), and angularly compressing the protrusionscan facilitate the navigation of the protrusions through the chordaetendineae 310.

For purposes of this description, certain aspects, advantages, and novelfeatures of the embodiments of this disclosure are described herein. Thedisclosed methods, apparatuses, and systems should not be construed aslimiting in any way. Instead, the present disclosure is directed towardall novel and nonobvious features and aspects of the various disclosedembodiments, alone and in various combinations and sub-combinations withone another. The methods, apparatuses, and systems are not limited toany specific aspect or feature or combination thereof, nor do thedisclosed embodiments require that any one or more specific advantagesbe present or problems be solved.

Although the operations of some of the disclosed methods are describedin a particular, sequential order for convenient presentation, it shouldbe understood that this manner of description encompasses rearrangement,unless a particular ordering is required by specific language. Forexample, operations described sequentially may in some cases berearranged or performed concurrently. Moreover, for the sake ofsimplicity, the attached figures may not show the various ways in whichthe disclosed methods can be used in conjunction with other methods. Asused herein, the terms “a”, “an” and “at least one” encompass one ormore of the specified element. That is, if two of a particular elementare present, one of these elements is also present and thus “an” elementis present. The terms “a plurality of” and “plural” mean two or more ofthe specified element.

As used herein, the term “and/or” used between the last two of a list ofelements means any one or more of the listed elements. For example, thephrase “A, B, and/or C” means “A”, “B”, “C”, “A and B” “A and C”, “B andC”, or “A, B and C.”

As used herein, the term “coupled” generally means physically coupled orlinked and does not exclude the presence of intermediate elementsbetween the coupled items absent specific contrary language.

In view of the many possible embodiments to which the principles of thedisclosed invention may be applied, it should be recognized that theillustrated embodiments are only preferred examples of the invention andshould not be taken as limiting the scope of the invention. Rather, thescope of the invention is defined by the following claims. We thereforeclaim as our invention all that comes within the scope and spirit ofthese claims.

We claim:
 1. An implantable prosthetic valve comprising: a radiallycollapsible and radially expandable annular main body having an inletend and an outlet end, the main body defining a central axis and a lumenextending therethrough from the inlet to the outlet, the main bodycomprising a network of struts interconnected at a plurality of nodes toform a plurality of open cells including a first circumferentiallyextending row of cells defining the inlet end of the main body and asecond circumferentially extending row of cells defining the outlet endof the main body, wherein each of the cells of the first row of cellscomprises four struts and wherein two of the four struts of each cell ofthe first row of cells intersect at nodes that define the inlet end ofthe main body at an atrial-most end of the prosthetic valve when theprosthetic valve is implanted in a native mitral valve of a patient; afirst flange coupled to the main body and extending radially away fromthe main body, the first flange comprising a plurality of radiallyextending first protrusions; a second flange coupled to the main bodyand extending radially away from the main body, the second flangecomprising a plurality of radially extending second protrusions; whereinthe first protrusions are angularly offset from the second protrusions;and a valve member supported within the lumen of the main body; whereinthe first flange and the second flange are closer to one another whenthe main body is in a radially expanded configuration than when the mainbody is in a radially collapsed configuration; wherein the first flangeand the second flange are coupled to the main body at locations locatedcloser to the inlet end than to the outlet end of the main body; whereinthe first flange extends radially away from the main body such that anangle between the central axis and the first flange is 90° when the mainbody is in the radially expanded configuration; wherein the secondflange extends radially away from the main body such that an anglebetween the central axis and the second flange is 90° when the main bodyis in the radially expanded configuration; and wherein each of the firstprotrusions and each of the second protrusions comprise a first radialstrut coupled to a first node of the main body and extending radiallyaway from the main body, a second radial strut coupled to a second nodeof the main body and extending radially away from the main body, a firstangled strut coupled at an angle to the first radial strut, and a secondangled strut coupled at an angle to the second radial strut and coupledto the first angled strut.
 2. The implantable prosthetic valve of claim1, wherein: a distance between the first flange and the second flangewhen the prosthetic valve is in the radially collapsed configuration isbetween about 4 mm and about 30 mm; and a distance between the firstflange and the second flange when the prosthetic valve is in theradially expanded configuration is between about 2 mm and about 20 mm.3. The implantable prosthetic valve of claim 1, wherein: the main bodycomprises a network of struts to form a plurality of open cells; thefirst protrusions are coupled to respective nodes of the main body in afirst circumferential row of nodes located at the inlet end of the mainbody; and the second protrusions are coupled to respective nodes of themain body in a second circumferential row of nodes, the second row ofnodes being the closest row of nodes in the network of struts to thefirst row of nodes.
 4. The implantable prosthetic valve of claim 1,wherein: the main body comprises a network of struts interconnected toform a plurality of open cells; the first protrusions are coupled torespective nodes of the main body in a first circumferential row ofnodes located at the inlet end of the main body; and the secondprotrusions are coupled to respective nodes of the main body in a secondcircumferential row of nodes, the nodes of the first and second rowsbeing situated in a single circumferential row of open cells.
 5. Theimplantable prosthetic valve of claim 1, wherein the first flangeextends radially away from the main body parallel to the second flange.6. The implantable prosthetic valve of claim 5, wherein each of thefirst and second flanges have a flat profile as viewed from a side ofthe prosthetic valve.
 7. An implantable prosthetic valve comprising: aradially collapsible and radially expandable frame comprising an annularmain body and first and second flanges coupled to the main body; themain body comprising a network of struts interconnected at a pluralityof nodes to form a plurality of open cells, including a firstcircumferentially extending row of cells defining an inlet end of theframe and a second circumferentially extending row of cells defining anoutlet end of the frame, the main body defining a lumen extendingtherethrough from the inlet end to the outlet end; the first flangecomprising a plurality of first protrusions connected to respectivenodes of the first row of cells at the inlet end of the frame andextending radially outwardly from the first row of cells; the secondflange comprising a plurality of second protrusions connected torespective nodes of the first row of cells and extending radiallyoutwardly from the first row of cells, wherein the nodes to which thesecond protrusions are connected are axially spaced from the nodes towhich the first protrusions are connected; and a valve member supportedwithin the lumen of the main body; wherein the first flange and thesecond flange are closer to one another when the main body is in aradially expanded configuration than when the main body is in a radiallycollapsed configuration.
 8. The implantable prosthetic valve of claim 7,wherein each of the cells of the first row of cells comprises fourstruts, and each of the plurality of first protrusions comprises firstand second radial struts connected to respective nodes of two adjacentcells of the first row of cells, and each of the plurality of secondprotrusions comprises first and second radial struts connected torespective nodes of one cell of the first row of cells.
 9. Theimplantable prosthetic valve of claim 7, wherein the main body iscylindrical.
 10. The implantable prosthetic valve of claim 7, whereinthe inlet end of the frame is an atrial-most end of the prosthetic valvewhen the prosthetic valve is implanted in a native mitral valve of apatient.
 11. An implantable prosthetic valve comprising: a radiallycollapsible and radially expandable frame comprising an annular mainbody and first and second flanges coupled to the main body; the mainbody comprising a network of struts interconnected at a plurality ofnodes to form a plurality of open cells, including a firstcircumferentially extending row of cells defining an inlet end of theframe and a second circumferentially extending row of cells defining anoutlet end of the frame, the main body defining a lumen extendingtherethrough from the inlet end to the outlet end; the first flangecomprising a plurality of first protrusions connected to respectivenodes of the first row of cells at the inlet end of the frame andextending radially outwardly from the first row of cells; the secondflange comprising a plurality of second protrusions connected torespective nodes of the first row of cells and extending radiallyoutwardly from the first row of cells; and a valve member supportedwithin the lumen of the main body; wherein the first flange and thesecond flange are closer to one another when the main body is in aradially expanded configuration than when the main body is in a radiallycollapsed configuration; and wherein the plurality of first protrusionsare connected to respective nodes at a middle of the first row of cells.12. An implantable prosthetic valve comprising: a radially collapsibleand radially expandable frame comprising an annular main body and firstand second flanges coupled to the main body; the main body comprising anetwork of struts interconnected at a plurality of nodes to form aplurality of open cells, including a first circumferentially extendingrow of cells defining an inlet end of the frame and a secondcircumferentially extending row of cells defining an outlet end of theframe, the main body defining a lumen extending therethrough from theinlet end to the outlet end; the first flange comprising a plurality offirst protrusions connected to respective nodes of the first row ofcells at the inlet end of the frame and extending radially outwardlyfrom the first row of cells; the second flange comprising a plurality ofsecond protrusions connected to respective nodes of the first row ofcells and extending radially outwardly from the first row of cells; anda valve member supported within the lumen of the main body; wherein thefirst flange and the second flange are closer to one another when themain body is in a radially expanded configuration than when the mainbody is in a radially collapsed configuration; wherein each of the cellsof the first row of cells comprises four struts, each of the pluralityof first protrusions comprises first and second radial struts connectedto respective nodes of two adjacent cells of the first row of cells, andeach of the plurality of second protrusions comprises first and secondradial struts connected to respective nodes of one cell of the first rowof cells; and wherein two of the four struts of each cell of the firstrow of cells intersect at nodes that define an atrial-most end of theframe when the prosthetic valve is implanted in a native mitral valve ofa patient.
 13. An implantable prosthetic mitral valve for implantationwithin a native mitral valve, the prosthetic valve comprising: aradially collapsible and radially expandable annular body defining acentral axis and a lumen extending therethrough from an inlet to anoutlet of the annular body, the annular body comprising a network ofstruts interconnected at a plurality of nodes to form a plurality ofopen cells; an atrial flange coupled to the annular body and extendingradially away from the annular body, the atrial flange comprising aplurality of radially extending atrial protrusions, wherein the atrialprotrusions are configured to engage an atrial side of the native mitralvalve; a ventricular flange coupled to the annular body and extendingradially away from the main body, the ventricular flange comprising aplurality of radially extending ventricular protrusions, wherein a tipof each of the ventricular protrusions points in a direction that issubstantially orthogonal to the central axis, wherein the ventricularprotrusions are configured to engage a ventricular side of the nativemitral valve; wherein the atrial protrusions are angularly offset fromthe ventricular protrusions; wherein the atrial flange and theventricular flange are closer to one another when the annular body is ina radially expanded configuration than when the annular body is in aradially collapsed configuration; wherein the atrial protrusions areconnected to a first set of nodes of the plurality of nodes and theventricular protrusions are connected to a second set of nodes of theplurality of nodes, wherein the first set of nodes is axially spacedfrom the second set of nodes; three angularly spaced, longitudinallyextending commissure support posts of fixed length extending in parallelwith each other from the ventricular flange toward a ventricular end ofthe prosthetic valve; and a valve member comprising three leafletscoupled to the commissure support posts, wherein the commissure supportposts support the leaflets below the ventricular flange within the leftventricle when the prosthetic valve is implanted within the nativemitral valve.
 14. The implantable prosthetic mitral valve of claim 13,wherein a tip of each of the atrial protrusions points in a directionthat is substantially orthogonal to the central axis.
 15. Theimplantable prosthetic mitral valve of claim 13, wherein the annularbody defines an annulus portion comprising a row of the plurality ofopen cells between the atrial flange and the ventricular flange sized tobe positioned within the native mitral valve annulus, and wherein thecommissure support posts have upper end portions connected to theannulus portion at the row of the plurality of open cells.